Device for monitoring an air supply flow or a volumetric air flow

Abstract

The invention relates to a device for monitoring an air supply flow or a volumetric air flow, in particular for ventilators which can also be applied for extremely low flow speeds and/or throughput rates. The aim of the invention is to produce a device cheaply and simply with essentially wear-free components which reacts to changes in the flow speed and/or the throughput rate without a time delay. Said aim is achieved, whereby the device comprises an approach flow device, the position of which may be altered relative to a mounting, against a retaining force F M and which may be impinged by the air flow for monitoring to generate a change in the position thereof. Furthermore, magnetic devices for the generation of a magnetic field dependent on the position of the approach flow device, detection means for recording the magnetic field and measuring means for generation of a measured signal dependent on the magnetic field are provided. The magnetic field forms at least a part of the retaining force F M .

1. Device for monitoring an air supply flow or a volumetric air flow, comprising
 an approach-flow component adapted to be struck by an air flow that is to be monitored so as to produce a change in its position; 
 a holder on which the approach-flow component is mounted but relative to which the approach-flow component can change its position against a retaining force F M ; 
 magnet components adapted to produce a magnetic field dependent on the position of the approach-flow component, the force of said magnetic field forming at least part of the retaining force F M ; 
 a detector adapted to detect the magnetic field; and 
 a signal generator adapted to generate a measurement signal that depends on the strength of the magnetic field, 
 wherein the approach-flow component is provided with at least one counterweight so that it can be installed regardless of the force of gravity and of its position. 
 
   
   
     2. Device according to  claim 1 , wherein the magnet components comprise a permanent magnet. 
   
   
     3. Device according to  claim 2 , wherein the permanent magnet is attached to the approach-flow component. 
   
   
     4. Device according to  claim 2 , wherein the permanent magnet is fixedly attached to the holder and a magnetic element is attached to the approach-flow component. 
   
   
     5. Device according to  claim 1 , wherein the approach-flow component comprises a flap rotatably suspended in such a way that the air flow exerts a moment of torque, on the flap, about its axis of suspension. 
   
   
     6. Device according to  claim 1 , wherein the approach-flow component is eccentrically seated and a larger area portion of the approach-flow component is provided as said counterweight. 
   
   
     7. Device according to  claim 1 , wherein the counterweight comprises at least parts of the magnet components. 
   
   
     8. Device according to  claim 1 , wherein the measurement means comprises a reed contact, which is disposed in a reed-contact switch. 
   
   
     9. Device according to  claim 8 , wherein the approach-flow component is mounted in such a way that it is in a resting state when the magnet component is retained by the retaining force F M  at the shortest distance to the reed-contact switch. 
   
   
     10. Device according to  claim 8 , wherein the reed-contact switch is disposed in such a way that in the magnetic field it generates at least part of the retaining force F M . 
   
   
     11. Device according to  claim 10 , wherein the position of the reed-contact switch can be adjusted with respect to its distance from the permanent magnet in order to provide an adjustment means whereby the retaining force F M  can be adjusted. 
   
   
     12. Device according to  claim 1 , wherein adjustment means are provided so that the retaining force F M  can be adjusted. 
   
   
     13. Device according to  claim 12 , wherein the adjustment means comprise additional magnetic elements that can be brought into the magnetic field. 
   
   
     14. Device according to  claim 12 , wherein an effective area of the approach-flow component can be altered. 
   
   
     15. Device according to  claim 14 , wherein the housing is constructed in such a way that the effective area of the approach-flow component can be altered by constructing the holder as a housing. 
   
   
     16. Device according to  claim 1 , wherein the holder is constructed as a housing and the measurement means are disposed in the housing.